Study On The Protective Effects Of Polysaccharides From Termitomyces Albuminosus On Alcoholic Liver Injury In Mice

Termitomyces albuminosus, also called "Jizongin" in Chinese,belongs to Basidiomycetes,Agaricales,Pleurotaceae and Tricholomataceae.The color of the fruit body of Termitomyces albuminosus is white, the texture is tender, and it has refreshing fragrance, it is a kind of famous wild edible fungi which contains of rich nutritious elements,especially some substances that have functions of health protection,such as saponin,polysaccharides,cellulase, polyphenol and so on. It was reported that Termitomyces albuminosus has protective effect on refreshment,analgesic,anti-inflammatory and antioxidant,in which polysaccharides was proposed to be the major active constituents of Termitomyces albuminosus. Thus the study was designed to investigate the effects of the polysaccharide from Termitomyces albuminosus on alcohol acute liver damage from three respects.1.The extraction and antioxidation in vitro of Termitomyces albuminosus polysaccharide.In order to measure the antioxidant activity of polysaccharide from Termitomyces albuminosus, we got the crude polysaccharide from Termitomyces albuminosus(CPTA) by the method of water extracting-alcohol precipitating,which assisted by Ultrasonic Cell Crusher.After three times of deproteinization using the method of Sevag,the CPTA become the refined polysaccharide from Termitomyces albuminosus (RPTA),the RPTA I-a was got by RPTA purification with DEAE-Cellulose52and Sepharose4B.Then we determined the bioactive substances composition of CPTA,RPTA and RPTA I-a,while their elimination of·OH、—O2-and reducing power were also assured.The results showed that CPTA had polysaccharide,protein, reduced sugar, total phenolics and flavone.The contents of polysaccharide and protein were respectively (32.032±0.488) g/100g and (3.215±0.517) g/100g.Compared with CPTA,RPTA had no total phenolics and flavone.The contents of polysaccharide and protein were (76.106±0.656) g/100g and(1.332±0.048)g/100g.The RPTA I-a obtained from RPTA barely had protein,its polysaccharide were(96.569±0.393)g/100g.The UV scanning spectrum showed that the RPTA I-a didn’t contain nucleic acid and protein,while the IR scanning suggested that RPTA I-a has Pyran ring carbon skeleton which was typical polysaccharide characteristic group.The antioxidation in vitro shows that the CPTA,RPTA and RPTA I-a had certain antioxidant activity,and its antioxidant ability increased with thepurity and concentration,which indicted that polysaccharide play the major role.2.Taking RPTA as the test material,the author established acute alcoholic hepalic injury model to investigate the protective effect of RPTA in mice from functional test and pathological section. The animals were randomly divided into normal control group, model control group, Bifendate (150mg/kg.bw)group and RPTA (100,200,400mg/kg.bw)groups.After housing for30days,50%alcohol (12mL/kg.bw) were administered orally into animals of all groups,except blank control group,to induce hepatotoxicity.The results showed that in the model control group the level of glutamic oxalacetic transaminase(GOT/ALT)、glutamic-pyruvic transaminase(GPT/AST)、 Triglyceride(TG)、Malondialdehyde(MDA) were obviously improved,while superoxide dismutase (SOD)、Glutathione peroxidase(GSH-Px)、Glutathione(GSH) were lower compared with the control group.The results suggested that alcohol could reduce the activity of antioxidative enzyme and content of non-enzyme substance, which leads to more peroxidation product of membrane lipids.While in the RPTA groups,the level of AST,ALT and MDA were decreased while the level of SOD,GSH-Px and GSH were increased,which showed that RPTA could help eliminate the injury of alcohol metabolism in varying degrees. Pathological section indicated that central vein in lobuli hepatics were expanded in model group,in addition, hepatic cord in hepar were arranged mussily, hepatocyte were swollen obviously and even liver cells were flakily necrotic.The lower dose group had less effect on histopathological change, while the middle group and high group had bigger and bigger effect on protect hepatocyte.Above results suggested that RPTA could improve the inhibiting ability and decrease the injury of hepatocyte.RPTA had positive effect on mice with alcohol-induced acute liver injury.3. The observation of ultrastructure in acute alcoholic hepatic injury in mice and detecting of changes in apoptotic pathway.In order to further clear the pathogenesis of Alcoholic liver disease, the study investigated the ultrastructure in acute alcoholic hepatic injury in mice and mRNA expression of Alcohol dehydrogenase2(ADH2)、Aldehyde dehydrogenase2(ALDH2) and Cytochrome P4502E1(CYP2E1) by RT-PCR.In the model group, members of lipid droplets and glycogen were found. The nuclear membranes were irregular and nucleoli shrank. Chromatin karyotin were in abnormal distribution. Duplicature of mitochondria were injured. The rough endoplasmic reticulum was found as expansion and degranulation and ribosome droped off. Cardinal symptom gradually got better in polysaccharide group. The RT-PCR results showed that in the model group the mRNA expression of CYP2E1was decreased while ADH2and ALDH2significantly increased compared with blank group. While in the highdose RPTA groups,the mRNA expression of the three genes were getting the level of the control group in varying degrees. Acute alcoholic liver injury could cause pathological changes in ultrastructure and the mRNA expression of CYP2E1decrease while ADH2, ALDH2increase. RPTA plays an protective role in acute alcoholic hepatic injury in mice by controlling the mRNA expression of ADH2, ALDH2and CYP2E1.